This invention relates to an apparatus that can perform dual functions of isolating and mixing two different fluids. The apparatus can be used to dilute or pre-mix one fluid with another and, when not in operation, completely isolates the two starting fluids from each other.
Many processes require mixing two different fluids or diluting one fluid with another. For example, liquid polyelectrolytes (polymers) used in various water treatment and wastewater treatment processes must be diluted with water to create solutions having small concentrations, say, up to approximately 10% polymer, by weight or volume. Due to the large amount of water required to achieve this level of dilution, it is usually more cost effective to transport the polymer ingredient to the site and to dilute it with water already available at the site.
The polymers to be diluted can be compositions such as polyelectrolytes, for example. Proper mixing of liquid polymers with water is not always easy. Most polymers can activate very quickly once they come into contact with water or aqueous compositions, and can form a highly viscous and sticky agglomeration if not promptly and thoroughly mixed with an appropriate amount of water. A positive means of mixing must be implemented to dilute the polymer effectively. The viscosity of a particular solution can vary in direct proportion to the percentage of polymer in the solution. In other words, as the percentage of polymer in the solution is increased, the viscosity of the solution is also increased, and vice versa. Inadequate or slow mixing of the liquid polymer with the water can result in excessive and undesirable coagulation of the mixture and consequent clogging or obstruction of system piping and components. Clogging can be so significant that a system might be rendered inoperable until it is cleaned and the obstruction is cleared.